[HN Gopher] Pig brain function under extracorporeal pulsatile ci...
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Pig brain function under extracorporeal pulsatile circulatory
control
Author : bookofjoe
Score : 41 points
Date : 2023-11-18 18:16 UTC (4 hours ago)
(HTM) web link (www.nature.com)
(TXT) w3m dump (www.nature.com)
| xeckr wrote:
| A literal brain in a vat.
| isoprophlex wrote:
| _To this end, blood flow to the head was surgically separated
| from the systemic circulation and full extracorporeal pulsatile
| circulatory control (EPCC) was delivered_
|
| On the whole, it doesn't sound like a very nice procedure for
| the brain (or the rest of the pig)
| cariaso wrote:
| 3.5 million pigs are slaughtered for food each day.
|
| 2 pig subjects "were sedated with an intramuscular injection
| of tiletamine and zolazepam (4-8 mg/kg of each, in equal
| amount), atropine (0.04 mg/kg) and buprenorphine (0.05
| mg/kg). They were then administered inhaled isoflurane,
| except during neurophysiological recording as noted below,
| and oxygen (2 L/min). These gases were applied first via
| snout mask and immediately afterwards via endotracheal
| intubation with mechanical ventilatory support. General
| anesthesia was maintained throughout the rest of the life of
| the animals, including euthanasia."
|
| That protocol was approved by some suitable committee, in
| accordance with the Animal Welfare Act and similar protocols.
| I think most people informed of the details and the purpose
| of the research would agree the benefits easily justify the
| cost of their sacrifice.
| j-pb wrote:
| I don't think that the absolute horrors that are the modern
| meat industry, somehow lessen the tragedy of animal
| testing.
| a1o wrote:
| So we are making progress to the future promised by Futurama.
| carbocation wrote:
| They address this but I still don't really understand why I
| should care about pulsatility. Humans can live for a very long
| time without pulsatile flow (LVAD). (And sure, to pre-empt
| critics: the needle has turned back towards at least intermittent
| pulsatility, but this is largely for device thrombosis
| prevention.)
|
| They seem to bring up theoretical concerns without addressing the
| practical (again, in human) successes of non-pulsatile flow.
| iancmceachern wrote:
| Excellent question.
|
| I've worked in the LVAD and artificial heart industry, designed
| several.
|
| You are right, that most modern LVADs are rotary pumps which
| are technically non pulsatile. I say technically because yes,
| if you test the pump on a bench of course it's not pulsatile.
| But once they're implanted, and working in concert with the
| native heart the net result is somewhere in between. You have
| more flow that you did before, less puksatile, but still
| pulsatile.
|
| The implant guidance for most lvads calls for the clinicians to
| lower the speed setting of the lvad until they can see the
| aortic valve intermittently opening and closing on echo. If
| they set the setting too high and the valve stays open, or too
| low and it doesn't often open, it will calcify in one of those
| two positions.
|
| If they follow this guidance, the net flow is pulsatile.
|
| Onto your question.
|
| Look up "pump head". This is what happens to the brain on truly
| non puksatile flow, like you get when your on extended periods
| of support on a heart lung bypass machine.
|
| Check out a company "ventriflo" who is working on a pulsatile
| pump in this space to overcome these traditional challenges. I
| helped design this too.
|
| Cheers!
| bobmaxup wrote:
| > Look up "pump head".
|
| https://en.wikipedia.org/wiki/Postperfusion_syndrome
| tomr75 wrote:
| Results in lower GI bleeding too (pulsation). Don't know the
| physics but ?less shear stress
| lifeisstillgood wrote:
| Ok. I'll bite.
|
| This strikes me as going too far.
|
| the justification (upfront which is not as usual for most papers
| I come across which explain what they did that was so cool first)
| is something like it's hard to determine if what drugs we give to
| a brain is just brain based or is the darn body getting involved
| too.
|
| But you know, if I understand that right, then we are mostly
| going to want to care about the brain and body together - cos
| that's how most of us function.
|
| I get it's an engineering challenge. I also get that
| experimenting with certain things is just off-limits, foetuses
| being the first thing that come to mind.
|
| I am a huge proponent for increasing science funding every day of
| the week, for undirected research because we don't know what we
| don't know, but sometimes we just need to say, find another way.
| chpatrick wrote:
| I think you would feel differently if one day your heart stops
| and the doctors can stop you from getting brain damage using
| this technology.
| LightMachine wrote:
| Exactly. That kind of anti-scientific propaganda is
| dangerous. OP shouldn't have so many upvotes.
| Teever wrote:
| I resent the attempt to tie the entirety of science to the
| use of animals in experiments.
|
| Someone can still be a strong proponent of the scientific
| method but be opposed to animal testing for moral reasons.
| chpatrick wrote:
| What's more moral, experimenting on one pig or letting
| thousands of people die who could be helped by your
| research?
| krisoft wrote:
| Or as an alternative question: is it less moral to do
| this experiment than eating the pig? Because society
| seems to be by far and large be okay with eating pigs.
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(page generated 2023-11-18 23:00 UTC)